Summary of Significant Accounting Policies (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net income (loss) - numerator
Net (loss) income	$ 20,105	$ (9,197)	$ 29,720	$ (12,073)
Less dividends to Class B shareholders - distributed earnings		0	0	(28)
Undistributed (loss) earnings	$ 20,105	$ (9,197)	$ 29,720	$ (12,101)
Weighted average common shares outstanding - denominator
Weighted average common shares outstanding for basic earnings (loss) per share	58,016	55,271	55,766	53,519
Weighted average common shares outstanding - Diluted	58,152	55,271	55,889	53,519
Class A [Member]
Weighted average common shares outstanding - denominator
Weighted average common shares outstanding for basic earnings (loss) per share	58,016	55,271	55,766	53,379
Dilutive effect of options and restricted stock units	136	0	123	0
Weighted average common shares outstanding - Diluted	58,152	55,271	55,889	53,379
Basic
Distributed earnings	$ 0.00	$ 0.00	$ 0.00	$ 0.00
Undistributed (loss) earnings	$ 0.35	$ (0.17)	$ 0.53	$ (0.23)
Total	$ 0.35	$ (0.17)	$ 0.53	$ (0.23)
Diluted
Distributed earnings			$ 0.00
Undistributed (loss) earnings	$ 0.35	$ (0.17)	$ 0.53	$ (0.23)
Total	$ 0.35	$ (0.17)	$ 0.53	$ (0.23)
Class B [Member]
Weighted average common shares outstanding - denominator
Weighted average common shares outstanding for basic earnings (loss) per share	0	0	0	140
Weighted average common shares outstanding - Diluted	0	0	0	140
Basic
Distributed earnings	$ 0.00	$ 0.00	$ 0.00	$ 0.20
Undistributed (loss) earnings	$ 0.00	$ 0.00	$ 0.00	$ (0.23)
Total	$ 0.00	$ 0.00	$ 0.00	$ (0.03)
Diluted
Distributed earnings	$ 0.00	$ 0.00	$ 0.00	$ 0.20
Undistributed (loss) earnings	$ 0.00	$ 0.00	$ 0.00	$ (0.23)
Total	$ 0.00	$ 0.00	$ 0.00	$ (0.03)